In the recent office environments, the quantity of document data to be managed increases greatly as the work becomes complex and the amount of information increases. For this reason, the need for searching a target document from a huge number of documents is even more increasing. By converting pieces of document information into electronic data and storing as document data, a document search apparatus or document search system is able to use this converted information upon searching a target document.
Various document search methods have been proposed including document attribute search which searches information (namely, attribute data) associated with document data, full text search which searches a character string contained in document data, and image data search which searches image data contained in the document data.
To execute these search methods, it is necessary to input a search key to a search apparatus (search engine). Unlike a search method such as attribute search or full text search that uses a character string as a key, the problem of image searching using image data as a key is how to allow a user to easily and simply designate or input such image search key.
For example, an image storage apparatus described in patent reference 1 obtains a search key by scanning with a scanner a document with an area designated in advance. Further, an image storage apparatus described in patent reference 2 extracts a search key by displaying, on a window, document data obtained by scanning with a scanner and designating an area to be used as a search key by using, e.g., a mouse. Still further, a similar image search apparatus described in patent reference 3 registers image data to be used as a search key in advance, and designates a search key among the registered image data.
Patent reference 1: Japanese Patent Laid-Open No. 5-274367
Patent reference 2: Japanese Patent Laid-Open No. 5-274368
Patent reference 3: Japanese Patent Laid-Open No. 10-340272